Melting glacier causes Canadian river to vanish in four days

The Guardian reported that the Slims river in Canada disappeared in four days as ice melt from the glacier changed the direction of its flow into another watercourse. Now, meltwater from the Kaskawulsh glacier is carried away from the Slims river and toward the Kaskawulsh river.

The disappearance of the Slims river, which was up to 150 metres at its widest point, is what scientists are calling “river piracy”, where the flow of one river is diverted into another.

For hundreds of years, the Slims river carried meltwater north from the Kaskawulsh glacier in Canada’s Yukon territory into the Kluane river, then into the Yukon river towards the Bering Sea. But in 2016, a lot of glacier ice melted so the drainage was tipped to the Alsek River, taking the meltwater to the Gulf of Alaska.

The scientists used drones to investigate what was happening. “We found the Slims riverbed was more or less dry,” said James Best, a geologist at the University of Illinois.

The landscape changed. Where the Slims used to flow, Dall sheep from Kluane National Park are now eating the fresh vegetation, in an area where they can be legally hunted. The air is now often turned into a dusty haze as winds make dust clouds out of the exposed riverbed. Fish populations are also changing.

Analysis shows that the changes can probably be attributed to climate change. The Yukon region is sparsely inhabited, but future river piracy could have huge effects on towns, villages and ecosystems.

Coral reef destruction in Australia

The BBC reported unheard of levels of coral bleaching in continuous years that has destroyed two thirds of Australia’s Great Barrier Reef. Bleaching is loss of algae and has affected a 1,500km (900 miles) of the reef, according to scientists.

Prof Terry Hughes and expert from James Cook University, said governments must address climate change to prevent bleaching. He said “Since 1998, we have seen four of these events and the gap between them has varied substantially, but this is the shortest gap we have seen”.

A graphic showing damage to the Great Barrier Reef in 2016 and 2017Image: ARC CENTRE OF EXCELLENCE FOR CORAL REEF STUDIES



healthy                                       dying (bleaching)                                   dead